Self-shifting to 4-Lo...YOW!!

I have a 2000 Jimmy, @60K, well taken care of and spoiled rotten. Recently she's gotten into her head to shift herself into 4-Lo when I start her up. Then (after much pushing of buttons) I finally get her into 2-Hi and drive for a short distance the 4-Lo light starts blinking again and if I stop, shifts to 4-lo. I repeat the process to get back to 2-hi. Then after a while the conditon disappears. I guess this is so I can't reproduce it for a mechanic. Anybody else have this problem, or know of a fix that doesn't involve a massive infusion of dollars?

I have a 2000 Jimmy, @60K, well taken care of and spoiled rotten. Recently she's gotten into her head to shift herself into 4-Lo when I start her up. Then (after much pushing of buttons) I finally get her into 2-Hi and drive for a short distance the 4-Lo light starts blinking again and if I stop, shifts to 4-lo. I repeat the process to get back to 2-hi. Then after a while the conditon disappears. I guess this is so I can't reproduce it for a mechanic. Anybody else have this problem, or know of a fix that doesn't involve a massive infusion of dollars?
Hey there, I have the same problem with my 1999 GMC Jimmy. I am trying to find out what the problem is also. It will also shift into 4wd hi and low while driving down the highway. I have replaced the control module found on the side floor of the passenger side and the actuator on the transfer case. If I find out anything or if you do, let's share this. Thank you.

Pampersman

Helpppppp,
I too have the self shifting problem. 1999 gmc jimmy 107k. Did anyone figure this out?

I am still stuck in 4LO myself, but I have done a lot of dismantling and rebuilding on the transfer case shifting parts. Sounds like you have a problem with the push button switch itself. It is small PC board with rubber inserts to force a contact when pushed. If anything either breaks loose or gets moved around inside the switch it will fall to the lowest point which happens to be the contact for the 4LO button. When jiggled around enough you can dislodge the piece enough to get it to shift to where you want, but it can shift back to 4Lo at any time and may even get stuck in 4LO permanently till either the switch is replaced or taken apart and the foreign matter removed and possibly glued back where it belongs. I found this problem in mine, but in my case that wasn't the offending part. If yours will switch back this is the most likely culprit. Good luck. I got this info from an answer to my thread about being stuck in 4LO. very good info.

This thread is too old, start a new one thanks.